1. Field of the Invention
The present invention relates to an ion detector for detecting positive ions and negative ions.
2. Related Background Art
Conventional ion detectors including conversion dynodes that emit secondary electrons by ion collisions, scintillators that emit light upon incidence of the secondary electrons emitted from the conversion dynodes, photodetectors that detect the light emitted by the scintillators have been known (refer to, for example, Japanese Patent Application Laid-Open No. H07-326315, French Patent Application Laid-Open No. 2658361 (FR2658361A1)). Here, a positive ion conversion dynode to which a negative potential is applied and a negative ion conversion dynode to which a positive potential is applied are separately provided for detection of positive ions and negative ions in some cases (refer to, for example, Japanese Patent Application Laid-Open No, H07-326315).